Abstract Thin films of ITO (Sn-doped In 2O 3) were coated on Corning #1737 glass substrates (50×50 mm 2) heated at 600 °C, after introducing an aerosol with air to a furnace heated at 620 °C. The aerosol was produced by ultrasonic vibration of 0.2 M In(III)-acetylacetonate together with 5 mol% Sn(IV)-bis-acetylacetonate-dibromide dissolved in acetylacetone. Film structure and electrical resistivity at room temperature depend on air flow rate: (1) at 10 l/min ITO films grew with (1 0 0)-preferred orientation because (4 0 0) and (8 0 0) peaks were clearly observed and the electrical resistivity was approximately (1–2)×10 −4 Ω cm; (2) when the air flow rate was reduced to 7.5 and 5 l/min, the (4 0 0) and (8 0 0) peak intensities became small and their resistivity was (2–4)×10 −4 Ω cm. The optical energy band gap (3.90 eV), which is estimated from the relationship between the square of the optical absorption coefficient times the frequency of the electromagnetic wave and the frequency near the absorption edge, is independent of film thickness and air flow rate. Some comments on the (1 0 0)-preferred orientation thin-film growth and on the resistivity change due to the flow rate are provided.